To reduce unnecessary radiation, the medical image scan happens only to the pre-selected regions of the patient. Because of the variation in patient body shapes, body sizes, clothing, and the like, a technician operating a medical imaging scanner may be faced with the difficult task of trying to determine, roughly, the hidden location of an internal organ or region of interest in a patient. The current workflow of patient scan range planning is determined by the technicians from low-dose topogram images, which results in extra radiation of the patients. The technician then manually positions the patient such that the region of interest is optimally positioned with respect to the scanner. The manual patient positioning process is time-consuming and costly.
To improve the manual patient positioning process, motion-sensing input devices (e.g., Microsoft Kinect) are used for coarse initial patient setup verification and alignment. However, this approach involves aligning the patient on a table based on a previously obtained CT scan in the diagnostic phase. Thus, a prior medical imaging scan (e.g., which may have already necessitated some degree of manual patient positioning and/or radiation exposure) is a prerequisite to this approach.
Generation of a synthetic topogram from an optical RGB-D sensor may assist the technicians to determine the patient's scan range without extra radiation. This method relies on searching for the best match between the queried RGB-D data and a large CT dataset, so it may take hours of computation time. In other approaches, patient re-alignment is used with the optical sensor, but requires that the surface data to belong to the same patient.